Swivel-plug attachment.



A. W. BUELL. SWIVEL PLUG ATTACHMENT.

APPLICATION FILED SEPT. 5, 1911.

1 028 429 Patented June 4, 1912.

Merl L/[Budf WM: y

snares arm ALBERT W. BUELL, OF ST. PAUL, IVIINNE$OTA, ASSIGNOR T FEDERAL ELECTRIC COMPANY, OF CHICAGO, ILLINOIS, A CORPOEATIQN O1? ILLINOIS.

'SlVIVlllL-PLUG' ATTACHMENT.

To all whom it may concern:

Be it known thatI, ALBERT W. BUELL. a c1tizen of the United States, and a resident of St. Paul, in the county of Ramsey andv State of Minnesota, have invented certain new and useful Improvementsin Swivel- Plug Attachments; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to sockets and consists of the matters hereinafter described and more particularly pointed Y out in the appended claims.

The object of the invention is to provid a plug attachment of simple and economical I screws to which the wire conductors are led I constructionwhich may be screwed into the electric socket without twisting the wires to which it is connected.

In the drawings-Figure 1 is a view representing my improved swivel plug attachment in side elevation. Fig. 9. is a view representing 1n side-elevation the swivel plug member. Fig. 3 1s a view represent-mg inside elevation the shell contact member.

Fig. at is a view representing a longitudinal section through the plug attachmenton-the line 44 of Fig. 1. Fig. 5 is a view representing a longitudinal section through the swivel plug on the line 5-5 of Fig. 2.

My improved plug attachment consists of two members,a rotati've, threaded, ringmember adapted to be screwed into the socket and which constitutes t-he metallic shell contact of the device and a plugmember on which the'first-named member is rotatively mounted and which, bears the center contact at one end and carries the binding posts or through laterally spaced longitudinal pas- I sages extending into its other end. A yielding spring contact carried by said plug member provides electric connection between one "from the rotative'ring member.

Referring now in detail tothat embodi-' of the binding posts and the metallic shell contact of the rotative ring member and at longitudinal withdrawal of the plug member ment of my invention illustrated in the drawings', indicates the rot-at-ive ring member, and 11,:theplug member which; carries the Specification of Letters Patent.

racemes same a, rare.

Application filed September 5, 1911. Serial No. 17,760;

connection for the wire conductors which is rotatively secured within the said ring memthe diameter of the interior oi -the shell contact 13, so that the inner margin of said i ring forms an inwardly extending, annular I shoulder 12 aboutwhich, as shown in thedrawings, the base of the said metallic shell is spun. The fiber sleeve 14 is externally screw-threaded and is rigidly engaged within the upper end of the shell which, as shown,

is screw-threaded internally as well as eX-' ternally. The exposed end 14* of the sleeve 14: is made conical in cross-section to facilitate its insertion into a socket. The internal diameter of said sleeve is the same as the diameter of the aperture in the flat ring 12. An insulating ring 15 surrounds the base. of the shell contact and bears at ower edge against the flat ring 12.

The plug member 11 is made-of insulatin material and has a base 11 and a reduced stem 11, the said base projecting radially beyond the stem to provide an annular shoulder 11. The stem 11 is of a length substan-' tially equal to the length of the ring member 10, and is of a diameter adapted to engage loosely within the flat ring 12 and within the sleeve 14: which provide a rotative bearing of the ring member on the stem of the plug member. Be-

tween the fiat ring 12' and the sleeve 14,

the inner surface of the metallic shell contact 13 is spaced rrom the stem 11, ofthe plug member. of the plugmember is cut away to pro- At one side the stem 11 vide a ilatrace 16 in which is formed a recess 16?.

17 indicates a' spring contact extending longitudinally downward from the stem end of the plug member and projecting away from and-at an angle to said stem. As

shown, said spring contact is bent back upon and in said groove is located a metal plate 19 secured in place by means of abolt or screw 20 which extends tr nsversely through the stem through a suitable aperture provided therein and through an aperture in the attaching plate 17 on said spring contact. A nut 20 threaded upon the end of said bolt secures said attaching member in place; Into the end of the metal plate 19 nearer the spring contact 17 is threaded a binding screw 21. tion is established bet-ween the binding screw 21' and the spring; contact 17, through the metal. plate 19, the screw 20 and the attaching plate 17* ofsaid contact.

The center contact consists of a pin 22 located in a cylindric recess in the end of the stem 11 and retained therein by a screw 23. which extends through a transverse aperture in the stem into a recess formed in said pin 22. Said screw 23 is located in a recess 23 formed in the surface of the stem 11 near its end and constitutes a binding screw for the attachment of one of the conducting wires, which it electrically connects with said center contact pin 22.

) The base 11 of the plug member is provided with a recess 24 to receive the conducting wires 25, 26, said recess opening into laterally spaced, longitudinally extending branch passages 25, 26, leading respectively to the recess containing the binding screw 23 and'to the transverse groove containing the binding screw 21.

' To assemble the device, the conducting wires 25, 26 are first inserted through .the respective passages 25, 26, and are secured to their associated binding screws 23 and 21- respectively. The stem of the plug member 11 is then pushed into the ring member 10 until the annular shoulder 11 of the plug member formed by its radially extending base engages against the flat ring 12 forming the base of the ring member. The spring contact, after it passes the annular shoulder 12, springs outward into engagement with .the interior of the metallic shell contact 13 with its end part 'in engagement with said shoulder, which, as described, is covered shell contact. Said spring contact 17 thus provides a lock to prevent the withdrawal of the plug memb'er'ffrom the ring member and Thus electrical connecaffords electric connection between the metallic shell contact 13 and the wire conductor 26 connected to the binding screws 21 the wire conductor 25 attached'to the other binding screw 23 havingelectric' connection with the center contact pin 22 at the end of the stemll of the plug member. It is thus apparent that while the two parts of the devicc are locked against relative longitudinal movement, either may be rotated with reference to the other.

In order that the plug may be withdrawn from the shell, as when the wires are to be connected or in case of repairs or otherwise, a transverse slot'30 is formed in the metallic shell adjacent its base, through which slot a s1. all tool may be inserted and brought to bear against the spring contact 17 so as to press the same inwardly toward the body of the stem, whereupon the plug member may be withdrawn from the ring member. "I claim as my invention- 1. A swivel plug attachment comprising a ring member having an externally threaded shell contact, a. plug member of in: sulating material on-which said ring member is rotatively mounted, said plug member being adapted for the attachment of con--- ductors, a center contact carried at the end of said plug member, interlocking devices carried respectively by said ring member and said plug member adapted to prevent longitudinal movement of said plug member with reference to said ring member, one of said interlocking devices being adapted to yield to permit the insertion of said plug member into said ring member, and the interlocking device carried by said plug member constituting an intermediate contact member having sliding engagement with the interior surface of said shell member.

2. A swivel plug attachment comprising a ring member having an externally threaded shell contact, a plug member of 1nsulating material on which said ring memberis rotatively mounted, a center contact carried at the end of said plug member, 1nterlocking devices carried respectlvely by said ring member and said plug member adapted to prevent longitudinal movement vices being adapted to yield to permit the insertion of said plug member into said ring member, and the interlocking device carried by said plug member COIIStItIJiZIIIgPIH intermediate v contact member hav1ng sliding engagement with the'interior surface of said shell member, said plug member being provided with longitudinally extending,

laterally separated passages opening through its base for conductors, and means carried by said plugmember for electr cally connecting said conductors to said intercontact.

mediate con-tact member and to said center 3. A swivel plug attachment comprising i a ring member including a threaded metal sulating material having a reduced stem on which said ring member is rotatively mounted and a base providing a radially extending annular shoulder located in abutting relation with the base of said ring member, a spring contact secured to said stem and adapted for abutting engagement with the annular shoulder of said ring member and-for sliding engagement with-the interior of said shell contact, a'binding screw having electric connection with said spring contact, a

center contact secured in the end of said stem, and a binding screw having electric connection with said center contact, said stem being provided with 'circumferentially spaced recesses in which said binding screws are located and with laterally spaced,

longitudinally extending passages opening through the base of said plug member for the conductor wires.

In testimony, that I, claim the foregoing as my invention I aflix my signature in the presence of two wltnesses, this 26th day of August A. I). 1911.

ALBERT W. BUELL. 

